Chain Rule Practice Questions

5 questions per page • Detailed step-by-step solutions

Question 6
Easy
The cost of 5 kgs of apples is Rs. 450. The cost of 12 dozen mangoes is Rs. 4320 and the cost of 4 kgs of oranges is Rs. 240. What is the total cost of 8 kg of apples, 8 dozen of mangoes and 8 kg of oranges?
A Rs. 3850
B Rs. 4080
C Rs. 4120
D Rs. 4250
Correct Answer: B

Explanation:

1 kg apple = 450 / 5 = Rs. 90. 1 dozen mango = 4320 / 12 = Rs. 360. 1 kg orange = 240 / 4 = Rs. 60. Total = 8 * (90 + 360 + 60) = 8 * 510 = Rs. 4080.
Question 7
Easy
An industrial loom weaves 0.128 metres of cloth every second. Approximately, how many seconds will it take for the loom to weave 25 metres of cloth?
A 178 seconds
B 195 seconds
C 204 seconds
D 215 seconds
Correct Answer: B

Explanation:

Rate of weaving = 0.128 metres/second. Time required to weave 25 metres = 25 / 0.128 = 25000 / 128 = 195.31 seconds ≈ 195 seconds.
Question 8
Easy
In a dairy farm, 40 cows eat 40 bags of husk in 40 days. In how many days will one cow eat one bag of husk?
A 1 day
B 20 days
C 40 days
D 80 days
Correct Answer: C

Explanation:

Using (M1 * D1) / W1 = (M2 * D2) / W2: (40 * 40) / 40 = (1 * D2) / 1 => 40 = D2. Hence, 1 cow eats 1 bag in 40 days.
Question 9
Medium
A garrison had provisions for a certain number of days. After 10 days, one-fifth of the men deserted, and it was found that the provisions would now last just as long as before. How long was that?
A 40 days
B 45 days
C 50 days
D 60 days
Correct Answer: C

Explanation:

Let original days = D. M * (D - 10) = (4/5 M) * D => D - 10 = 4/5 D => 1/5 D = 10 => D = 50 days.
Question 10
Easy
50 people consume 350 kg of rice in 30 days. In how many days will 35 people consume 50 kg of rice?
A 5 days
B 6.12 days
C 7 days
D 8 days
Correct Answer: B

Explanation:

Using (M1 * D1) / W1 = (M2 * D2) / W2: (50 * 30) / 350 = (35 * D2) / 50 => 1500 / 350 = 35 * D2 / 50 => 30 / 7 = 7 * D2 / 10 => D2 = 300 / 49 ≈ 6.12 days.